Manufacture of clamps



(No Model.) .2 Sheets-Sheet 1. A. A. STROM. MANUFACTURE OP'OLAMPS.

No. 459,859.. Patented Sept. 22, 1891.

UNITED STATES PATENT OFFICE.

AXEL A. STROM, OF AUSTIN, ASSIGNOR TO THE STROM MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS.

MANUFACTURE OF CLAMPS.

SPECIFICATION forming part of Letters Patent No. 459,859, dated September 22, 1891. Application filed June 16, 1891. Serial No. 396,513. No model.)

have invented anew and useful Improvement in the Manufacture of Clamps, of which the following is a specification.

My invention relates to an improved method of and improved means for manufacturing clamps such as those illustrated and described in Letters Patent of the United States, No.

374,505, granted me on the 6th day of December, 1887, and employed for clamping together the rails and other parts of a railway-frog.

To practice my improved method I proceed, generally stated, as follows: I bend a heated metal bar forming the blank toward its opposite ends to or approximately to right angles, therebyproducing three sides of a square or approximate square, and then I bend the bent ends over an interposed form toward each other, thereby forming the inclined jaws.

The means I employ for practicing my improved method are illustrated in the accompanying drawings, in which- Figure l isaview iii-side elevation of a portion of a horizontally-reciprocating bendingmachine supporting on its bed the dies of peculiar construction for producing the first bend in the blank. Fig. 2 is a broken plan view of the same. Fig. 3 is a perspective view showing the blank after having been acted on by thedies shown in Figs. 1 and 2. Fig.4 is a broken plan view of the bending-machine like that presented in Fig. 2, but showing the dies for bending the bent ends of the partlyfinished blank over an interposed form, as indicated by dotted lines, to produce the jaws and finish the formation of the clamp. Fig. 5 is a plan view showing the dies brought together and as having thereby formed the jaw at one end of the clamp. Fig. 6 is a similar view of the dies after having formed the jaw at each end of the clamp. Fig. 7 is a perspective view of the finished clamp enlarged over the scale thereof represented in preceding figures.

For the first part of the operation,in which the bent blank illustrated in Fig. 3 is produced, I employ a male die A and a female die 13.

The die A comprises a rectangular tongue 0' on a head 7'. The die B comprises a baseplate p,provided with a cross-bar g on its upper side near one edge, at which it is provided with a bearing-plate 0. From near the opposite ends of the cross-bar q extend parallel arms n n, joined at their free ends by a bar a and forming with the latter a rectangular frame, in the corners of which and the baseplate 19 are journaled the rollers m m. I operate the dies on a suitable horizontally-reciprocating bending-machine C, preferablyof the well-known bulldozer class, as illustrated. To that end I fasten the die B sta tionarily in horizontal position on the bedZ of the machine and adjust it with relation to the stroke of the horizontally-reciprocating head by means of set-screws in bearings 50 near the forward end of the bed and engaging at their inner ends the bearing-plate 0. Near 70 one roller m on the bed I is a stop or gage U for setting the blank D, (represented in position by dotted lines in Fig. 2,) which is adjusted to extend across both rollers m. The die A is fastened at its head r to the reciproeating head 70 of the machine C in a manner to cause its plate r to extend horizontally in the plane between the rollers m. \Vith the parts in the relative positions described and shown in Fig. 2, by advancing the die A against the blank D (which has been previously heated) it is bent by being forced between the rollers to the rectangular shape illustrated in Fig. 3, the outer corners being thereby curved,

as shown at 00'. To produce from that form by a second operation the finished clamp E presented in Fig. 7, I employ a bending-die F and a holder G. The die F is like the male die A, inasmuch as it has a head h, at which it is bolted to the reciprocating head is of the go machine C, and a horizontally-extending plate h, which, however, is provided in its forward end with a semicircular recess 1', terminating at one end in an outwardly and laterally curved tongue 2'. The holder G comprises a 5 three-sided metal frame conforming along the two inner surfaces of the sides g and g to the lines of two adjacent sides of the blank when bent to the form illustrated in Fig. 3 and at the junction of its sides g and g to the curvatoo ture as at an outer corner of the blank so bent. The latter is adjusted in the holder G, as represented by dotted lines in Fig. 4, with a form H, comprising a fiat metal bar beveled on one side toward the opposite edges interposed between the bent ends of the partly-finished blank. Thus one of the bent ends of the blank D is presented to the die F, which is then advanced and bends the bent end of the blank over the form II from a different point than that ofthe bend :r and regularly continuing the curve of the latter, producing a jaw f. \Vhen one jaw has been so formed, the partlyfinished clamp is reversed in the holder G to present its other end :0 to the die F, which acts similarly on that end to produce a jaw f. If the stroke of the head kbe sufficiently long, instead of a mere holder G, the latter may be supplanted by a stationary die the counterpart of the die F, when by a single advance movement of the latter both bent ends as of the blank will. be formed into jaws f simultaneously.

\Vhat 1 claim as new, and desire to secure by Letters Patent, is-

1. The method of forming a clamp E, which consists in first bending-a suitable metal blank toward its opposite ends to or approximately to right angles and then bending the said bent ends over a form into jaws f, substantially as described.

2. The method of forming a clamp E, which consists in first bending a suitable metal blank toward its opposite ends to or approximately to right angles and curying the outer corners, as at at, and then bending the said bent ends into jaws f from points beyond the angles of the previous bends, and thereby continuing the curves described by the corners 01:, substantially as described.

3. In combination, dies A and B for use in forming clamps E, the die A comprising a plate 0', having a head 0" adapted to be secured to a reciprocating head It, and the die 13 comprising a plate 17, carrying a rectangular frame, and rollers 'm, journaled at opposite corners of the frame, substantially as described.

at. A forming-die F for use in manufacturing clamps E, comprising a head h and a plate 71/, having a recess 2' in its forward end, and an outwardly-curved extension 2" at one end of the recess, substantially as described.

AXEL A. STROM. In presence of- J. WV. DYRENFORTH, M. J. Fnosr. 

